1. Field of the Invention
The present invention relates to a one-way clutch, and in particular to a one-way clutch that has a simplified structure and enhances transmission thereof.
2. Description of the Related Art
A one-way clutch generally transmits a mechanism in a single direction and rotates without transmission in the opposite direction.
Referring to FIG. 1, U.S. Pat. No. 3,844,392 discloses a conventional one-way clutch 1 having the aforementioned function. The one-way clutch 1 includes a passive member 10, an active member 20, a roller 30 and a spring 40. The passive member 10 includes a receiving portion 11 formed therein. The active member 20 includes an engaging groove 21 formed therein. The spring 40 is disposed in the receiving portion 11. The roller 30 is disposed on the spring 40 and in the receiving portion 11. The spring 40 provides an axial force to the roller 30. Additionally, the engaging groove 21 includes a curved surface 22 and a slanted surface 23.
As shown in FIG. 1, when the active member 20 rotates counterclockwise, the roller 30 is driven by the curved surface 22 of the engaging groove 21, thus causing the passive member 10 to rotate counterclockwise. At this point, the one-way clutch 1 performs one-way transmission. When the active member 20, on the other hand, rotates clockwise, the roller 30 slides on the slanted surface 23 of the engaging groove 21 and compresses the spring 40. The roller 30 is then pushed into the receiving portion 11 of the passive member 10, causing the active member 20 to slide on the outer circumferential surface of the passive member 10 and on the roller 30. At this point, the one-way clutch 1 only rotates and does not perform any transmission.
The conventional one-way clutch 1 has many drawbacks as follows.
Since the spring 40 is disposed in the passive member 10, manufacture of the one-way clutch 1 is difficult, increasing manufacturing costs thereof.
The active member 20 has only one engaging groove 21. When the one-way clutch 1 performs transmission, the active member 20 may require a large amount of rotation to position the roller 30 into the engaging groove 21. Accordingly, the length of time the roller 30 contacts the active member 20 is long. Additionally, the operation generates noise.
Accordingly, since the active member 20 may require a large amount of rotation to position the roller 30 into the engaging groove 21, transmission efficiency of the one-way clutch 1 is reduced.